1889 lines
51 KiB
C
1889 lines
51 KiB
C
/* Handle SunOS and SVR4 shared libraries for GDB, the GNU Debugger.
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Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1998
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Free Software Foundation, Inc.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
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#include "defs.h"
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/* This file is only compilable if link.h is available. */
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#ifdef HAVE_LINK_H
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#include <sys/types.h>
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#include <signal.h>
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#include "gdb_string.h"
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#include <sys/param.h>
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#include <fcntl.h>
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#include <unistd.h>
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#ifndef SVR4_SHARED_LIBS
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/* SunOS shared libs need the nlist structure. */
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#include <a.out.h>
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#else
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#include "elf/external.h"
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#endif
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#include <link.h>
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#include "symtab.h"
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#include "bfd.h"
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#include "symfile.h"
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#include "objfiles.h"
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#include "gdbcore.h"
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#include "command.h"
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#include "target.h"
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#include "frame.h"
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#include "gnu-regex.h"
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#include "inferior.h"
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#include "environ.h"
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#include "language.h"
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#include "gdbcmd.h"
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#define MAX_PATH_SIZE 512 /* FIXME: Should be dynamic */
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/* On SVR4 systems, a list of symbols in the dynamic linker where
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GDB can try to place a breakpoint to monitor shared library
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events.
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If none of these symbols are found, or other errors occur, then
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SVR4 systems will fall back to using a symbol as the "startup
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mapping complete" breakpoint address. */
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#ifdef SVR4_SHARED_LIBS
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static char *solib_break_names[] = {
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"r_debug_state",
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"_r_debug_state",
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"_dl_debug_state",
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"rtld_db_dlactivity",
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NULL
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};
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#endif
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#define BKPT_AT_SYMBOL 1
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#if defined (BKPT_AT_SYMBOL) && defined (SVR4_SHARED_LIBS)
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static char *bkpt_names[] = {
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#ifdef SOLIB_BKPT_NAME
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SOLIB_BKPT_NAME, /* Prefer configured name if it exists. */
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#endif
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"_start",
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"main",
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NULL
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};
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#endif
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/* Symbols which are used to locate the base of the link map structures. */
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#ifndef SVR4_SHARED_LIBS
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static char *debug_base_symbols[] = {
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"_DYNAMIC",
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"_DYNAMIC__MGC",
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NULL
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};
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#endif
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static char *main_name_list[] = {
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"main_$main",
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NULL
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};
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/* local data declarations */
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#ifndef SVR4_SHARED_LIBS
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#define LM_ADDR(so) ((so) -> lm.lm_addr)
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#define LM_NEXT(so) ((so) -> lm.lm_next)
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#define LM_NAME(so) ((so) -> lm.lm_name)
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/* Test for first link map entry; first entry is a shared library. */
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#define IGNORE_FIRST_LINK_MAP_ENTRY(x) (0)
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static struct link_dynamic dynamic_copy;
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static struct link_dynamic_2 ld_2_copy;
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static struct ld_debug debug_copy;
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static CORE_ADDR debug_addr;
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static CORE_ADDR flag_addr;
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#else /* SVR4_SHARED_LIBS */
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#define LM_ADDR(so) ((so) -> lm.l_addr)
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#define LM_NEXT(so) ((so) -> lm.l_next)
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#define LM_NAME(so) ((so) -> lm.l_name)
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/* Test for first link map entry; first entry is the exec-file. */
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#define IGNORE_FIRST_LINK_MAP_ENTRY(x) ((x).l_prev == NULL)
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static struct r_debug debug_copy;
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char shadow_contents[BREAKPOINT_MAX]; /* Stash old bkpt addr contents */
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#endif /* !SVR4_SHARED_LIBS */
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struct so_list {
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struct so_list *next; /* next structure in linked list */
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struct link_map lm; /* copy of link map from inferior */
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struct link_map *lmaddr; /* addr in inferior lm was read from */
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CORE_ADDR lmend; /* upper addr bound of mapped object */
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char so_name[MAX_PATH_SIZE]; /* shared object lib name (FIXME) */
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char symbols_loaded; /* flag: symbols read in yet? */
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char from_tty; /* flag: print msgs? */
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struct objfile *objfile; /* objfile for loaded lib */
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struct section_table *sections;
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struct section_table *sections_end;
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struct section_table *textsection;
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bfd *abfd;
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};
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static struct so_list *so_list_head; /* List of known shared objects */
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static CORE_ADDR debug_base; /* Base of dynamic linker structures */
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static CORE_ADDR breakpoint_addr; /* Address where end bkpt is set */
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static int solib_cleanup_queued = 0; /* make_run_cleanup called */
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extern int
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fdmatch PARAMS ((int, int)); /* In libiberty */
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/* Local function prototypes */
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static void
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do_clear_solib PARAMS ((PTR));
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static int
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match_main PARAMS ((char *));
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static void
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special_symbol_handling PARAMS ((struct so_list *));
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static void
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sharedlibrary_command PARAMS ((char *, int));
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static int
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enable_break PARAMS ((void));
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static void
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info_sharedlibrary_command PARAMS ((char *, int));
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static int
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symbol_add_stub PARAMS ((char *));
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static struct so_list *
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find_solib PARAMS ((struct so_list *));
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static struct link_map *
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first_link_map_member PARAMS ((void));
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static CORE_ADDR
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locate_base PARAMS ((void));
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static int
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solib_map_sections PARAMS ((char *));
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#ifdef SVR4_SHARED_LIBS
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static CORE_ADDR
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elf_locate_base PARAMS ((void));
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#else
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static int
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disable_break PARAMS ((void));
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static void
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allocate_rt_common_objfile PARAMS ((void));
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static void
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solib_add_common_symbols PARAMS ((struct rtc_symb *));
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#endif
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/* If non-zero, this is a prefix that will be added to the front of the name
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shared libraries with an absolute filename for loading. */
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static char *solib_absolute_prefix = NULL;
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/* If non-empty, this is a search path for loading non-absolute shared library
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symbol files. This takes precedence over the environment variables PATH
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and LD_LIBRARY_PATH. */
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static char *solib_search_path = NULL;
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/*
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LOCAL FUNCTION
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solib_map_sections -- open bfd and build sections for shared lib
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SYNOPSIS
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static int solib_map_sections (struct so_list *so)
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DESCRIPTION
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Given a pointer to one of the shared objects in our list
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of mapped objects, use the recorded name to open a bfd
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descriptor for the object, build a section table, and then
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relocate all the section addresses by the base address at
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which the shared object was mapped.
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FIXMES
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In most (all?) cases the shared object file name recorded in the
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dynamic linkage tables will be a fully qualified pathname. For
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cases where it isn't, do we really mimic the systems search
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mechanism correctly in the below code (particularly the tilde
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expansion stuff?).
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*/
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static int
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solib_map_sections (arg)
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char *arg;
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{
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struct so_list *so = (struct so_list *) arg; /* catch_errors bogon */
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char *filename;
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char *scratch_pathname;
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int scratch_chan;
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struct section_table *p;
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struct cleanup *old_chain;
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bfd *abfd;
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filename = tilde_expand (so -> so_name);
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if (solib_absolute_prefix && ROOTED_P (filename))
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/* Prefix shared libraries with absolute filenames with
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SOLIB_ABSOLUTE_PREFIX. */
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{
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char *pfxed_fn;
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int pfx_len;
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pfx_len = strlen (solib_absolute_prefix);
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/* Remove trailing slashes. */
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while (pfx_len > 0 && SLASH_P (solib_absolute_prefix[pfx_len - 1]))
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pfx_len--;
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pfxed_fn = xmalloc (pfx_len + strlen (filename) + 1);
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strcpy (pfxed_fn, solib_absolute_prefix);
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strcat (pfxed_fn, filename);
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free (filename);
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filename = pfxed_fn;
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}
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old_chain = make_cleanup (free, filename);
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scratch_chan = -1;
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if (solib_search_path)
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scratch_chan = openp (solib_search_path,
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1, filename, O_RDONLY, 0, &scratch_pathname);
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if (scratch_chan < 0)
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scratch_chan = openp (get_in_environ (inferior_environ, "PATH"),
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1, filename, O_RDONLY, 0, &scratch_pathname);
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if (scratch_chan < 0)
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{
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scratch_chan = openp (get_in_environ
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(inferior_environ, "LD_LIBRARY_PATH"),
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1, filename, O_RDONLY, 0, &scratch_pathname);
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}
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if (scratch_chan < 0)
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{
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perror_with_name (filename);
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}
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/* Leave scratch_pathname allocated. abfd->name will point to it. */
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abfd = bfd_fdopenr (scratch_pathname, gnutarget, scratch_chan);
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if (!abfd)
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{
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close (scratch_chan);
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error ("Could not open `%s' as an executable file: %s",
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scratch_pathname, bfd_errmsg (bfd_get_error ()));
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}
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/* Leave bfd open, core_xfer_memory and "info files" need it. */
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so -> abfd = abfd;
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abfd -> cacheable = true;
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/* copy full path name into so_name, so that later symbol_file_add can find
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it */
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if (strlen (scratch_pathname) >= MAX_PATH_SIZE)
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error ("Full path name length of shared library exceeds MAX_PATH_SIZE in so_list structure.");
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strcpy (so->so_name, scratch_pathname);
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if (!bfd_check_format (abfd, bfd_object))
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{
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error ("\"%s\": not in executable format: %s.",
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scratch_pathname, bfd_errmsg (bfd_get_error ()));
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}
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if (build_section_table (abfd, &so -> sections, &so -> sections_end))
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{
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error ("Can't find the file sections in `%s': %s",
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bfd_get_filename (abfd), bfd_errmsg (bfd_get_error ()));
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}
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for (p = so -> sections; p < so -> sections_end; p++)
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{
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/* Relocate the section binding addresses as recorded in the shared
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object's file by the base address to which the object was actually
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mapped. */
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p -> addr += (CORE_ADDR) LM_ADDR (so);
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p -> endaddr += (CORE_ADDR) LM_ADDR (so);
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so -> lmend = (CORE_ADDR) max (p -> endaddr, so -> lmend);
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if (STREQ (p -> the_bfd_section -> name, ".text"))
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{
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so -> textsection = p;
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}
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}
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/* Free the file names, close the file now. */
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do_cleanups (old_chain);
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return (1);
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}
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#ifndef SVR4_SHARED_LIBS
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/* Allocate the runtime common object file. */
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static void
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allocate_rt_common_objfile ()
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{
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struct objfile *objfile;
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struct objfile *last_one;
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objfile = (struct objfile *) xmalloc (sizeof (struct objfile));
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memset (objfile, 0, sizeof (struct objfile));
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objfile -> md = NULL;
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obstack_specify_allocation (&objfile -> psymbol_cache.cache, 0, 0,
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xmalloc, free);
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obstack_specify_allocation (&objfile -> psymbol_obstack, 0, 0, xmalloc,
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free);
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obstack_specify_allocation (&objfile -> symbol_obstack, 0, 0, xmalloc,
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free);
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obstack_specify_allocation (&objfile -> type_obstack, 0, 0, xmalloc,
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free);
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objfile -> name = mstrsave (objfile -> md, "rt_common");
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/* Add this file onto the tail of the linked list of other such files. */
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objfile -> next = NULL;
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if (object_files == NULL)
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object_files = objfile;
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else
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{
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for (last_one = object_files;
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last_one -> next;
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last_one = last_one -> next);
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last_one -> next = objfile;
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}
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rt_common_objfile = objfile;
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}
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/* Read all dynamically loaded common symbol definitions from the inferior
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and put them into the minimal symbol table for the runtime common
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objfile. */
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static void
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solib_add_common_symbols (rtc_symp)
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struct rtc_symb *rtc_symp;
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{
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struct rtc_symb inferior_rtc_symb;
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struct nlist inferior_rtc_nlist;
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int len;
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char *name;
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/* Remove any runtime common symbols from previous runs. */
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if (rt_common_objfile != NULL && rt_common_objfile -> minimal_symbol_count)
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{
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obstack_free (&rt_common_objfile -> symbol_obstack, 0);
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obstack_specify_allocation (&rt_common_objfile -> symbol_obstack, 0, 0,
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xmalloc, free);
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rt_common_objfile -> minimal_symbol_count = 0;
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rt_common_objfile -> msymbols = NULL;
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}
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init_minimal_symbol_collection ();
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make_cleanup (discard_minimal_symbols, 0);
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while (rtc_symp)
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{
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read_memory ((CORE_ADDR) rtc_symp,
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(char *) &inferior_rtc_symb,
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sizeof (inferior_rtc_symb));
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read_memory ((CORE_ADDR) inferior_rtc_symb.rtc_sp,
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(char *) &inferior_rtc_nlist,
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sizeof(inferior_rtc_nlist));
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if (inferior_rtc_nlist.n_type == N_COMM)
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{
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/* FIXME: The length of the symbol name is not available, but in the
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current implementation the common symbol is allocated immediately
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behind the name of the symbol. */
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len = inferior_rtc_nlist.n_value - inferior_rtc_nlist.n_un.n_strx;
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name = xmalloc (len);
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read_memory ((CORE_ADDR) inferior_rtc_nlist.n_un.n_name, name, len);
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/* Allocate the runtime common objfile if necessary. */
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if (rt_common_objfile == NULL)
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allocate_rt_common_objfile ();
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prim_record_minimal_symbol (name, inferior_rtc_nlist.n_value,
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mst_bss, rt_common_objfile);
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free (name);
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}
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rtc_symp = inferior_rtc_symb.rtc_next;
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}
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/* Install any minimal symbols that have been collected as the current
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minimal symbols for the runtime common objfile. */
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install_minimal_symbols (rt_common_objfile);
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}
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#endif /* SVR4_SHARED_LIBS */
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#ifdef SVR4_SHARED_LIBS
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static CORE_ADDR
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bfd_lookup_symbol PARAMS ((bfd *, char *));
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/*
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LOCAL FUNCTION
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bfd_lookup_symbol -- lookup the value for a specific symbol
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SYNOPSIS
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CORE_ADDR bfd_lookup_symbol (bfd *abfd, char *symname)
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DESCRIPTION
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An expensive way to lookup the value of a single symbol for
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bfd's that are only temporary anyway. This is used by the
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shared library support to find the address of the debugger
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interface structures in the shared library.
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Note that 0 is specifically allowed as an error return (no
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such symbol).
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*/
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static CORE_ADDR
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bfd_lookup_symbol (abfd, symname)
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bfd *abfd;
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char *symname;
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{
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unsigned int storage_needed;
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asymbol *sym;
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asymbol **symbol_table;
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unsigned int number_of_symbols;
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unsigned int i;
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struct cleanup *back_to;
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CORE_ADDR symaddr = 0;
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storage_needed = bfd_get_symtab_upper_bound (abfd);
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if (storage_needed > 0)
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{
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symbol_table = (asymbol **) xmalloc (storage_needed);
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back_to = make_cleanup (free, (PTR)symbol_table);
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number_of_symbols = bfd_canonicalize_symtab (abfd, symbol_table);
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for (i = 0; i < number_of_symbols; i++)
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{
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sym = *symbol_table++;
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if (STREQ (sym -> name, symname))
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{
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/* Bfd symbols are section relative. */
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symaddr = sym -> value + sym -> section -> vma;
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break;
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}
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}
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do_cleanups (back_to);
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}
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return (symaddr);
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}
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#ifdef HANDLE_SVR4_EXEC_EMULATORS
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/*
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Solaris BCP (the part of Solaris which allows it to run SunOS4
|
|
a.out files) throws in another wrinkle. Solaris does not fill
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in the usual a.out link map structures when running BCP programs,
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the only way to get at them is via groping around in the dynamic
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linker.
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The dynamic linker and it's structures are located in the shared
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|
C library, which gets run as the executable's "interpreter" by
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the kernel.
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|
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Note that we can assume nothing about the process state at the time
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we need to find these structures. We may be stopped on the first
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instruction of the interpreter (C shared library), the first
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instruction of the executable itself, or somewhere else entirely
|
|
(if we attached to the process for example).
|
|
*/
|
|
|
|
static char *debug_base_symbols[] = {
|
|
"r_debug", /* Solaris 2.3 */
|
|
"_r_debug", /* Solaris 2.1, 2.2 */
|
|
NULL
|
|
};
|
|
|
|
static int
|
|
look_for_base PARAMS ((int, CORE_ADDR));
|
|
|
|
/*
|
|
|
|
LOCAL FUNCTION
|
|
|
|
look_for_base -- examine file for each mapped address segment
|
|
|
|
SYNOPSYS
|
|
|
|
static int look_for_base (int fd, CORE_ADDR baseaddr)
|
|
|
|
DESCRIPTION
|
|
|
|
This function is passed to proc_iterate_over_mappings, which
|
|
causes it to get called once for each mapped address space, with
|
|
an open file descriptor for the file mapped to that space, and the
|
|
base address of that mapped space.
|
|
|
|
Our job is to find the debug base symbol in the file that this
|
|
fd is open on, if it exists, and if so, initialize the dynamic
|
|
linker structure base address debug_base.
|
|
|
|
Note that this is a computationally expensive proposition, since
|
|
we basically have to open a bfd on every call, so we specifically
|
|
avoid opening the exec file.
|
|
*/
|
|
|
|
static int
|
|
look_for_base (fd, baseaddr)
|
|
int fd;
|
|
CORE_ADDR baseaddr;
|
|
{
|
|
bfd *interp_bfd;
|
|
CORE_ADDR address = 0;
|
|
char **symbolp;
|
|
|
|
/* If the fd is -1, then there is no file that corresponds to this
|
|
mapped memory segment, so skip it. Also, if the fd corresponds
|
|
to the exec file, skip it as well. */
|
|
|
|
if (fd == -1
|
|
|| (exec_bfd != NULL
|
|
&& fdmatch (fileno ((GDB_FILE *)(exec_bfd -> iostream)), fd)))
|
|
{
|
|
return (0);
|
|
}
|
|
|
|
/* Try to open whatever random file this fd corresponds to. Note that
|
|
we have no way currently to find the filename. Don't gripe about
|
|
any problems we might have, just fail. */
|
|
|
|
if ((interp_bfd = bfd_fdopenr ("unnamed", gnutarget, fd)) == NULL)
|
|
{
|
|
return (0);
|
|
}
|
|
if (!bfd_check_format (interp_bfd, bfd_object))
|
|
{
|
|
/* FIXME-leak: on failure, might not free all memory associated with
|
|
interp_bfd. */
|
|
bfd_close (interp_bfd);
|
|
return (0);
|
|
}
|
|
|
|
/* Now try to find our debug base symbol in this file, which we at
|
|
least know to be a valid ELF executable or shared library. */
|
|
|
|
for (symbolp = debug_base_symbols; *symbolp != NULL; symbolp++)
|
|
{
|
|
address = bfd_lookup_symbol (interp_bfd, *symbolp);
|
|
if (address != 0)
|
|
{
|
|
break;
|
|
}
|
|
}
|
|
if (address == 0)
|
|
{
|
|
/* FIXME-leak: on failure, might not free all memory associated with
|
|
interp_bfd. */
|
|
bfd_close (interp_bfd);
|
|
return (0);
|
|
}
|
|
|
|
/* Eureka! We found the symbol. But now we may need to relocate it
|
|
by the base address. If the symbol's value is less than the base
|
|
address of the shared library, then it hasn't yet been relocated
|
|
by the dynamic linker, and we have to do it ourself. FIXME: Note
|
|
that we make the assumption that the first segment that corresponds
|
|
to the shared library has the base address to which the library
|
|
was relocated. */
|
|
|
|
if (address < baseaddr)
|
|
{
|
|
address += baseaddr;
|
|
}
|
|
debug_base = address;
|
|
/* FIXME-leak: on failure, might not free all memory associated with
|
|
interp_bfd. */
|
|
bfd_close (interp_bfd);
|
|
return (1);
|
|
}
|
|
#endif /* HANDLE_SVR4_EXEC_EMULATORS */
|
|
|
|
/*
|
|
|
|
LOCAL FUNCTION
|
|
|
|
elf_locate_base -- locate the base address of dynamic linker structs
|
|
for SVR4 elf targets.
|
|
|
|
SYNOPSIS
|
|
|
|
CORE_ADDR elf_locate_base (void)
|
|
|
|
DESCRIPTION
|
|
|
|
For SVR4 elf targets the address of the dynamic linker's runtime
|
|
structure is contained within the dynamic info section in the
|
|
executable file. The dynamic section is also mapped into the
|
|
inferior address space. Because the runtime loader fills in the
|
|
real address before starting the inferior, we have to read in the
|
|
dynamic info section from the inferior address space.
|
|
If there are any errors while trying to find the address, we
|
|
silently return 0, otherwise the found address is returned.
|
|
|
|
*/
|
|
|
|
static CORE_ADDR
|
|
elf_locate_base ()
|
|
{
|
|
sec_ptr dyninfo_sect;
|
|
int dyninfo_sect_size;
|
|
CORE_ADDR dyninfo_addr;
|
|
char *buf;
|
|
char *bufend;
|
|
|
|
/* Find the start address of the .dynamic section. */
|
|
dyninfo_sect = bfd_get_section_by_name (exec_bfd, ".dynamic");
|
|
if (dyninfo_sect == NULL)
|
|
return 0;
|
|
dyninfo_addr = bfd_section_vma (exec_bfd, dyninfo_sect);
|
|
|
|
/* Read in .dynamic section, silently ignore errors. */
|
|
dyninfo_sect_size = bfd_section_size (exec_bfd, dyninfo_sect);
|
|
buf = alloca (dyninfo_sect_size);
|
|
if (target_read_memory (dyninfo_addr, buf, dyninfo_sect_size))
|
|
return 0;
|
|
|
|
/* Find the DT_DEBUG entry in the the .dynamic section.
|
|
For mips elf we look for DT_MIPS_RLD_MAP, mips elf apparently has
|
|
no DT_DEBUG entries. */
|
|
#ifndef TARGET_ELF64
|
|
for (bufend = buf + dyninfo_sect_size;
|
|
buf < bufend;
|
|
buf += sizeof (Elf32_External_Dyn))
|
|
{
|
|
Elf32_External_Dyn *x_dynp = (Elf32_External_Dyn *)buf;
|
|
long dyn_tag;
|
|
CORE_ADDR dyn_ptr;
|
|
|
|
dyn_tag = bfd_h_get_32 (exec_bfd, (bfd_byte *) x_dynp->d_tag);
|
|
if (dyn_tag == DT_NULL)
|
|
break;
|
|
else if (dyn_tag == DT_DEBUG)
|
|
{
|
|
dyn_ptr = bfd_h_get_32 (exec_bfd, (bfd_byte *) x_dynp->d_un.d_ptr);
|
|
return dyn_ptr;
|
|
}
|
|
#ifdef DT_MIPS_RLD_MAP
|
|
else if (dyn_tag == DT_MIPS_RLD_MAP)
|
|
{
|
|
char pbuf[TARGET_PTR_BIT / HOST_CHAR_BIT];
|
|
|
|
/* DT_MIPS_RLD_MAP contains a pointer to the address
|
|
of the dynamic link structure. */
|
|
dyn_ptr = bfd_h_get_32 (exec_bfd, (bfd_byte *) x_dynp->d_un.d_ptr);
|
|
if (target_read_memory (dyn_ptr, pbuf, sizeof (pbuf)))
|
|
return 0;
|
|
return extract_unsigned_integer (pbuf, sizeof (pbuf));
|
|
}
|
|
#endif
|
|
}
|
|
#else /* ELF64 */
|
|
for (bufend = buf + dyninfo_sect_size;
|
|
buf < bufend;
|
|
buf += sizeof (Elf64_External_Dyn))
|
|
{
|
|
Elf64_External_Dyn *x_dynp = (Elf64_External_Dyn *)buf;
|
|
long dyn_tag;
|
|
CORE_ADDR dyn_ptr;
|
|
|
|
dyn_tag = bfd_h_get_64 (exec_bfd, (bfd_byte *) x_dynp->d_tag);
|
|
if (dyn_tag == DT_NULL)
|
|
break;
|
|
else if (dyn_tag == DT_DEBUG)
|
|
{
|
|
dyn_ptr = bfd_h_get_64 (exec_bfd, (bfd_byte *) x_dynp->d_un.d_ptr);
|
|
return dyn_ptr;
|
|
}
|
|
}
|
|
#endif
|
|
|
|
/* DT_DEBUG entry not found. */
|
|
return 0;
|
|
}
|
|
|
|
#endif /* SVR4_SHARED_LIBS */
|
|
|
|
/*
|
|
|
|
LOCAL FUNCTION
|
|
|
|
locate_base -- locate the base address of dynamic linker structs
|
|
|
|
SYNOPSIS
|
|
|
|
CORE_ADDR locate_base (void)
|
|
|
|
DESCRIPTION
|
|
|
|
For both the SunOS and SVR4 shared library implementations, if the
|
|
inferior executable has been linked dynamically, there is a single
|
|
address somewhere in the inferior's data space which is the key to
|
|
locating all of the dynamic linker's runtime structures. This
|
|
address is the value of the debug base symbol. The job of this
|
|
function is to find and return that address, or to return 0 if there
|
|
is no such address (the executable is statically linked for example).
|
|
|
|
For SunOS, the job is almost trivial, since the dynamic linker and
|
|
all of it's structures are statically linked to the executable at
|
|
link time. Thus the symbol for the address we are looking for has
|
|
already been added to the minimal symbol table for the executable's
|
|
objfile at the time the symbol file's symbols were read, and all we
|
|
have to do is look it up there. Note that we explicitly do NOT want
|
|
to find the copies in the shared library.
|
|
|
|
The SVR4 version is a bit more complicated because the address
|
|
is contained somewhere in the dynamic info section. We have to go
|
|
to a lot more work to discover the address of the debug base symbol.
|
|
Because of this complexity, we cache the value we find and return that
|
|
value on subsequent invocations. Note there is no copy in the
|
|
executable symbol tables.
|
|
|
|
*/
|
|
|
|
static CORE_ADDR
|
|
locate_base ()
|
|
{
|
|
|
|
#ifndef SVR4_SHARED_LIBS
|
|
|
|
struct minimal_symbol *msymbol;
|
|
CORE_ADDR address = 0;
|
|
char **symbolp;
|
|
|
|
/* For SunOS, we want to limit the search for the debug base symbol to the
|
|
executable being debugged, since there is a duplicate named symbol in the
|
|
shared library. We don't want the shared library versions. */
|
|
|
|
for (symbolp = debug_base_symbols; *symbolp != NULL; symbolp++)
|
|
{
|
|
msymbol = lookup_minimal_symbol (*symbolp, NULL, symfile_objfile);
|
|
if ((msymbol != NULL) && (SYMBOL_VALUE_ADDRESS (msymbol) != 0))
|
|
{
|
|
address = SYMBOL_VALUE_ADDRESS (msymbol);
|
|
return (address);
|
|
}
|
|
}
|
|
return (0);
|
|
|
|
#else /* SVR4_SHARED_LIBS */
|
|
|
|
/* Check to see if we have a currently valid address, and if so, avoid
|
|
doing all this work again and just return the cached address. If
|
|
we have no cached address, try to locate it in the dynamic info
|
|
section for ELF executables. */
|
|
|
|
if (debug_base == 0)
|
|
{
|
|
if (exec_bfd != NULL
|
|
&& bfd_get_flavour (exec_bfd) == bfd_target_elf_flavour)
|
|
debug_base = elf_locate_base ();
|
|
#ifdef HANDLE_SVR4_EXEC_EMULATORS
|
|
/* Try it the hard way for emulated executables. */
|
|
else if (inferior_pid != 0 && target_has_execution)
|
|
proc_iterate_over_mappings (look_for_base);
|
|
#endif
|
|
}
|
|
return (debug_base);
|
|
|
|
#endif /* !SVR4_SHARED_LIBS */
|
|
|
|
}
|
|
|
|
/*
|
|
|
|
LOCAL FUNCTION
|
|
|
|
first_link_map_member -- locate first member in dynamic linker's map
|
|
|
|
SYNOPSIS
|
|
|
|
static struct link_map *first_link_map_member (void)
|
|
|
|
DESCRIPTION
|
|
|
|
Read in a copy of the first member in the inferior's dynamic
|
|
link map from the inferior's dynamic linker structures, and return
|
|
a pointer to the copy in our address space.
|
|
*/
|
|
|
|
static struct link_map *
|
|
first_link_map_member ()
|
|
{
|
|
struct link_map *lm = NULL;
|
|
|
|
#ifndef SVR4_SHARED_LIBS
|
|
|
|
read_memory (debug_base, (char *) &dynamic_copy, sizeof (dynamic_copy));
|
|
if (dynamic_copy.ld_version >= 2)
|
|
{
|
|
/* It is a version that we can deal with, so read in the secondary
|
|
structure and find the address of the link map list from it. */
|
|
read_memory ((CORE_ADDR) dynamic_copy.ld_un.ld_2, (char *) &ld_2_copy,
|
|
sizeof (struct link_dynamic_2));
|
|
lm = ld_2_copy.ld_loaded;
|
|
}
|
|
|
|
#else /* SVR4_SHARED_LIBS */
|
|
|
|
read_memory (debug_base, (char *) &debug_copy, sizeof (struct r_debug));
|
|
/* FIXME: Perhaps we should validate the info somehow, perhaps by
|
|
checking r_version for a known version number, or r_state for
|
|
RT_CONSISTENT. */
|
|
lm = debug_copy.r_map;
|
|
|
|
#endif /* !SVR4_SHARED_LIBS */
|
|
|
|
return (lm);
|
|
}
|
|
|
|
/*
|
|
|
|
LOCAL FUNCTION
|
|
|
|
find_solib -- step through list of shared objects
|
|
|
|
SYNOPSIS
|
|
|
|
struct so_list *find_solib (struct so_list *so_list_ptr)
|
|
|
|
DESCRIPTION
|
|
|
|
This module contains the routine which finds the names of any
|
|
loaded "images" in the current process. The argument in must be
|
|
NULL on the first call, and then the returned value must be passed
|
|
in on subsequent calls. This provides the capability to "step" down
|
|
the list of loaded objects. On the last object, a NULL value is
|
|
returned.
|
|
|
|
The arg and return value are "struct link_map" pointers, as defined
|
|
in <link.h>.
|
|
*/
|
|
|
|
static struct so_list *
|
|
find_solib (so_list_ptr)
|
|
struct so_list *so_list_ptr; /* Last lm or NULL for first one */
|
|
{
|
|
struct so_list *so_list_next = NULL;
|
|
struct link_map *lm = NULL;
|
|
struct so_list *new;
|
|
|
|
if (so_list_ptr == NULL)
|
|
{
|
|
/* We are setting up for a new scan through the loaded images. */
|
|
if ((so_list_next = so_list_head) == NULL)
|
|
{
|
|
/* We have not already read in the dynamic linking structures
|
|
from the inferior, lookup the address of the base structure. */
|
|
debug_base = locate_base ();
|
|
if (debug_base != 0)
|
|
{
|
|
/* Read the base structure in and find the address of the first
|
|
link map list member. */
|
|
lm = first_link_map_member ();
|
|
}
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* We have been called before, and are in the process of walking
|
|
the shared library list. Advance to the next shared object. */
|
|
if ((lm = LM_NEXT (so_list_ptr)) == NULL)
|
|
{
|
|
/* We have hit the end of the list, so check to see if any were
|
|
added, but be quiet if we can't read from the target any more. */
|
|
int status = target_read_memory ((CORE_ADDR) so_list_ptr -> lmaddr,
|
|
(char *) &(so_list_ptr -> lm),
|
|
sizeof (struct link_map));
|
|
if (status == 0)
|
|
{
|
|
lm = LM_NEXT (so_list_ptr);
|
|
}
|
|
else
|
|
{
|
|
lm = NULL;
|
|
}
|
|
}
|
|
so_list_next = so_list_ptr -> next;
|
|
}
|
|
if ((so_list_next == NULL) && (lm != NULL))
|
|
{
|
|
/* Get next link map structure from inferior image and build a local
|
|
abbreviated load_map structure */
|
|
new = (struct so_list *) xmalloc (sizeof (struct so_list));
|
|
memset ((char *) new, 0, sizeof (struct so_list));
|
|
new -> lmaddr = lm;
|
|
/* Add the new node as the next node in the list, or as the root
|
|
node if this is the first one. */
|
|
if (so_list_ptr != NULL)
|
|
{
|
|
so_list_ptr -> next = new;
|
|
}
|
|
else
|
|
{
|
|
so_list_head = new;
|
|
|
|
if (! solib_cleanup_queued)
|
|
{
|
|
make_run_cleanup (do_clear_solib);
|
|
solib_cleanup_queued = 1;
|
|
}
|
|
|
|
}
|
|
so_list_next = new;
|
|
read_memory ((CORE_ADDR) lm, (char *) &(new -> lm),
|
|
sizeof (struct link_map));
|
|
/* For SVR4 versions, the first entry in the link map is for the
|
|
inferior executable, so we must ignore it. For some versions of
|
|
SVR4, it has no name. For others (Solaris 2.3 for example), it
|
|
does have a name, so we can no longer use a missing name to
|
|
decide when to ignore it. */
|
|
if (!IGNORE_FIRST_LINK_MAP_ENTRY (new -> lm))
|
|
{
|
|
int errcode;
|
|
char *buffer;
|
|
target_read_string ((CORE_ADDR) LM_NAME (new), &buffer,
|
|
MAX_PATH_SIZE - 1, &errcode);
|
|
if (errcode != 0)
|
|
{
|
|
warning ("find_solib: Can't read pathname for load map: %s\n",
|
|
safe_strerror (errcode));
|
|
return (so_list_next);
|
|
}
|
|
strncpy (new -> so_name, buffer, MAX_PATH_SIZE - 1);
|
|
new -> so_name[MAX_PATH_SIZE - 1] = '\0';
|
|
free (buffer);
|
|
catch_errors (solib_map_sections, (char *) new,
|
|
"Error while mapping shared library sections:\n",
|
|
RETURN_MASK_ALL);
|
|
}
|
|
}
|
|
return (so_list_next);
|
|
}
|
|
|
|
/* A small stub to get us past the arg-passing pinhole of catch_errors. */
|
|
|
|
static int
|
|
symbol_add_stub (arg)
|
|
char *arg;
|
|
{
|
|
register struct so_list *so = (struct so_list *) arg; /* catch_errs bogon */
|
|
CORE_ADDR text_addr = 0;
|
|
|
|
if (so -> textsection)
|
|
text_addr = so -> textsection -> addr;
|
|
else if (so -> abfd != NULL)
|
|
{
|
|
asection *lowest_sect;
|
|
|
|
/* If we didn't find a mapped non zero sized .text section, set up
|
|
text_addr so that the relocation in symbol_file_add does no harm. */
|
|
|
|
lowest_sect = bfd_get_section_by_name (so -> abfd, ".text");
|
|
if (lowest_sect == NULL)
|
|
bfd_map_over_sections (so -> abfd, find_lowest_section,
|
|
(PTR) &lowest_sect);
|
|
if (lowest_sect)
|
|
text_addr = bfd_section_vma (so -> abfd, lowest_sect)
|
|
+ (CORE_ADDR) LM_ADDR (so);
|
|
}
|
|
|
|
ALL_OBJFILES (so -> objfile)
|
|
{
|
|
if (strcmp (so -> objfile -> name, so -> so_name) == 0)
|
|
return 1;
|
|
}
|
|
so -> objfile =
|
|
symbol_file_add (so -> so_name, so -> from_tty,
|
|
text_addr,
|
|
0, 0, 0);
|
|
return (1);
|
|
}
|
|
|
|
/* This function will check the so name to see if matches the main list.
|
|
In some system the main object is in the list, which we want to exclude */
|
|
|
|
static int match_main (soname)
|
|
char *soname;
|
|
{
|
|
char **mainp;
|
|
|
|
for (mainp = main_name_list; *mainp != NULL; mainp++)
|
|
{
|
|
if (strcmp (soname, *mainp) == 0)
|
|
return (1);
|
|
}
|
|
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
|
|
GLOBAL FUNCTION
|
|
|
|
solib_add -- add a shared library file to the symtab and section list
|
|
|
|
SYNOPSIS
|
|
|
|
void solib_add (char *arg_string, int from_tty,
|
|
struct target_ops *target)
|
|
|
|
DESCRIPTION
|
|
|
|
*/
|
|
|
|
void
|
|
solib_add (arg_string, from_tty, target)
|
|
char *arg_string;
|
|
int from_tty;
|
|
struct target_ops *target;
|
|
{
|
|
register struct so_list *so = NULL; /* link map state variable */
|
|
|
|
/* Last shared library that we read. */
|
|
struct so_list *so_last = NULL;
|
|
|
|
char *re_err;
|
|
int count;
|
|
int old;
|
|
|
|
if ((re_err = re_comp (arg_string ? arg_string : ".")) != NULL)
|
|
{
|
|
error ("Invalid regexp: %s", re_err);
|
|
}
|
|
|
|
/* Add the shared library sections to the section table of the
|
|
specified target, if any. */
|
|
if (target)
|
|
{
|
|
/* Count how many new section_table entries there are. */
|
|
so = NULL;
|
|
count = 0;
|
|
while ((so = find_solib (so)) != NULL)
|
|
{
|
|
if (so -> so_name[0] && !match_main (so -> so_name))
|
|
{
|
|
count += so -> sections_end - so -> sections;
|
|
}
|
|
}
|
|
|
|
if (count)
|
|
{
|
|
int update_coreops;
|
|
|
|
/* We must update the to_sections field in the core_ops structure
|
|
here, otherwise we dereference a potential dangling pointer
|
|
for each call to target_read/write_memory within this routine. */
|
|
update_coreops = core_ops.to_sections == target->to_sections;
|
|
|
|
/* Reallocate the target's section table including the new size. */
|
|
if (target -> to_sections)
|
|
{
|
|
old = target -> to_sections_end - target -> to_sections;
|
|
target -> to_sections = (struct section_table *)
|
|
xrealloc ((char *)target -> to_sections,
|
|
(sizeof (struct section_table)) * (count + old));
|
|
}
|
|
else
|
|
{
|
|
old = 0;
|
|
target -> to_sections = (struct section_table *)
|
|
xmalloc ((sizeof (struct section_table)) * count);
|
|
}
|
|
target -> to_sections_end = target -> to_sections + (count + old);
|
|
|
|
/* Update the to_sections field in the core_ops structure
|
|
if needed. */
|
|
if (update_coreops)
|
|
{
|
|
core_ops.to_sections = target->to_sections;
|
|
core_ops.to_sections_end = target->to_sections_end;
|
|
}
|
|
|
|
/* Add these section table entries to the target's table. */
|
|
while ((so = find_solib (so)) != NULL)
|
|
{
|
|
if (so -> so_name[0])
|
|
{
|
|
count = so -> sections_end - so -> sections;
|
|
memcpy ((char *) (target -> to_sections + old),
|
|
so -> sections,
|
|
(sizeof (struct section_table)) * count);
|
|
old += count;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Now add the symbol files. */
|
|
while ((so = find_solib (so)) != NULL)
|
|
{
|
|
if (so -> so_name[0] && re_exec (so -> so_name) &&
|
|
!match_main (so -> so_name))
|
|
{
|
|
so -> from_tty = from_tty;
|
|
if (so -> symbols_loaded)
|
|
{
|
|
if (from_tty)
|
|
{
|
|
printf_unfiltered ("Symbols already loaded for %s\n", so -> so_name);
|
|
}
|
|
}
|
|
else if (catch_errors
|
|
(symbol_add_stub, (char *) so,
|
|
"Error while reading shared library symbols:\n",
|
|
RETURN_MASK_ALL))
|
|
{
|
|
so_last = so;
|
|
so -> symbols_loaded = 1;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Getting new symbols may change our opinion about what is
|
|
frameless. */
|
|
if (so_last)
|
|
reinit_frame_cache ();
|
|
|
|
if (so_last)
|
|
special_symbol_handling (so_last);
|
|
}
|
|
|
|
/*
|
|
|
|
LOCAL FUNCTION
|
|
|
|
info_sharedlibrary_command -- code for "info sharedlibrary"
|
|
|
|
SYNOPSIS
|
|
|
|
static void info_sharedlibrary_command ()
|
|
|
|
DESCRIPTION
|
|
|
|
Walk through the shared library list and print information
|
|
about each attached library.
|
|
*/
|
|
|
|
static void
|
|
info_sharedlibrary_command (ignore, from_tty)
|
|
char *ignore;
|
|
int from_tty;
|
|
{
|
|
register struct so_list *so = NULL; /* link map state variable */
|
|
int header_done = 0;
|
|
int addr_width;
|
|
char *addr_fmt;
|
|
|
|
if (exec_bfd == NULL)
|
|
{
|
|
printf_unfiltered ("No exec file.\n");
|
|
return;
|
|
}
|
|
|
|
#ifndef TARGET_ELF64
|
|
addr_width = 8+4;
|
|
addr_fmt = "08l";
|
|
#else
|
|
addr_width = 16+4;
|
|
addr_fmt = "016l";
|
|
#endif
|
|
|
|
while ((so = find_solib (so)) != NULL)
|
|
{
|
|
if (so -> so_name[0])
|
|
{
|
|
if (!header_done)
|
|
{
|
|
printf_unfiltered("%-*s%-*s%-12s%s\n", addr_width, "From",
|
|
addr_width, "To", "Syms Read",
|
|
"Shared Object Library");
|
|
header_done++;
|
|
}
|
|
|
|
printf_unfiltered ("%-*s", addr_width,
|
|
local_hex_string_custom ((unsigned long) LM_ADDR (so),
|
|
addr_fmt));
|
|
printf_unfiltered ("%-*s", addr_width,
|
|
local_hex_string_custom ((unsigned long) so -> lmend,
|
|
addr_fmt));
|
|
printf_unfiltered ("%-12s", so -> symbols_loaded ? "Yes" : "No");
|
|
printf_unfiltered ("%s\n", so -> so_name);
|
|
}
|
|
}
|
|
if (so_list_head == NULL)
|
|
{
|
|
printf_unfiltered ("No shared libraries loaded at this time.\n");
|
|
}
|
|
}
|
|
|
|
/*
|
|
|
|
GLOBAL FUNCTION
|
|
|
|
solib_address -- check to see if an address is in a shared lib
|
|
|
|
SYNOPSIS
|
|
|
|
char * solib_address (CORE_ADDR address)
|
|
|
|
DESCRIPTION
|
|
|
|
Provides a hook for other gdb routines to discover whether or
|
|
not a particular address is within the mapped address space of
|
|
a shared library. Any address between the base mapping address
|
|
and the first address beyond the end of the last mapping, is
|
|
considered to be within the shared library address space, for
|
|
our purposes.
|
|
|
|
For example, this routine is called at one point to disable
|
|
breakpoints which are in shared libraries that are not currently
|
|
mapped in.
|
|
*/
|
|
|
|
char *
|
|
solib_address (address)
|
|
CORE_ADDR address;
|
|
{
|
|
register struct so_list *so = 0; /* link map state variable */
|
|
|
|
while ((so = find_solib (so)) != NULL)
|
|
{
|
|
if (so -> so_name[0])
|
|
{
|
|
if ((address >= (CORE_ADDR) LM_ADDR (so)) &&
|
|
(address < (CORE_ADDR) so -> lmend))
|
|
return (so->so_name);
|
|
}
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
/* Called by free_all_symtabs */
|
|
|
|
void
|
|
clear_solib()
|
|
{
|
|
struct so_list *next;
|
|
char *bfd_filename;
|
|
|
|
while (so_list_head)
|
|
{
|
|
if (so_list_head -> sections)
|
|
{
|
|
free ((PTR)so_list_head -> sections);
|
|
}
|
|
if (so_list_head -> abfd)
|
|
{
|
|
bfd_filename = bfd_get_filename (so_list_head -> abfd);
|
|
if (!bfd_close (so_list_head -> abfd))
|
|
warning ("cannot close \"%s\": %s",
|
|
bfd_filename, bfd_errmsg (bfd_get_error ()));
|
|
}
|
|
else
|
|
/* This happens for the executable on SVR4. */
|
|
bfd_filename = NULL;
|
|
|
|
next = so_list_head -> next;
|
|
if (bfd_filename)
|
|
free ((PTR)bfd_filename);
|
|
free ((PTR)so_list_head);
|
|
so_list_head = next;
|
|
}
|
|
debug_base = 0;
|
|
}
|
|
|
|
static void
|
|
do_clear_solib (dummy)
|
|
PTR dummy;
|
|
{
|
|
solib_cleanup_queued = 0;
|
|
clear_solib ();
|
|
}
|
|
|
|
#ifdef SVR4_SHARED_LIBS
|
|
|
|
/* Return 1 if PC lies in the dynamic symbol resolution code of the
|
|
SVR4 run time loader. */
|
|
|
|
static CORE_ADDR interp_text_sect_low;
|
|
static CORE_ADDR interp_text_sect_high;
|
|
static CORE_ADDR interp_plt_sect_low;
|
|
static CORE_ADDR interp_plt_sect_high;
|
|
|
|
int
|
|
in_svr4_dynsym_resolve_code (pc)
|
|
CORE_ADDR pc;
|
|
{
|
|
return ((pc >= interp_text_sect_low && pc < interp_text_sect_high)
|
|
|| (pc >= interp_plt_sect_low && pc < interp_plt_sect_high)
|
|
|| in_plt_section (pc, NULL));
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
|
|
LOCAL FUNCTION
|
|
|
|
disable_break -- remove the "mapping changed" breakpoint
|
|
|
|
SYNOPSIS
|
|
|
|
static int disable_break ()
|
|
|
|
DESCRIPTION
|
|
|
|
Removes the breakpoint that gets hit when the dynamic linker
|
|
completes a mapping change.
|
|
|
|
*/
|
|
|
|
#ifndef SVR4_SHARED_LIBS
|
|
|
|
static int
|
|
disable_break ()
|
|
{
|
|
int status = 1;
|
|
|
|
#ifndef SVR4_SHARED_LIBS
|
|
|
|
int in_debugger = 0;
|
|
|
|
/* Read the debugger structure from the inferior to retrieve the
|
|
address of the breakpoint and the original contents of the
|
|
breakpoint address. Remove the breakpoint by writing the original
|
|
contents back. */
|
|
|
|
read_memory (debug_addr, (char *) &debug_copy, sizeof (debug_copy));
|
|
|
|
/* Set `in_debugger' to zero now. */
|
|
|
|
write_memory (flag_addr, (char *) &in_debugger, sizeof (in_debugger));
|
|
|
|
breakpoint_addr = (CORE_ADDR) debug_copy.ldd_bp_addr;
|
|
write_memory (breakpoint_addr, (char *) &debug_copy.ldd_bp_inst,
|
|
sizeof (debug_copy.ldd_bp_inst));
|
|
|
|
#else /* SVR4_SHARED_LIBS */
|
|
|
|
/* Note that breakpoint address and original contents are in our address
|
|
space, so we just need to write the original contents back. */
|
|
|
|
if (memory_remove_breakpoint (breakpoint_addr, shadow_contents) != 0)
|
|
{
|
|
status = 0;
|
|
}
|
|
|
|
#endif /* !SVR4_SHARED_LIBS */
|
|
|
|
/* For the SVR4 version, we always know the breakpoint address. For the
|
|
SunOS version we don't know it until the above code is executed.
|
|
Grumble if we are stopped anywhere besides the breakpoint address. */
|
|
|
|
if (stop_pc != breakpoint_addr)
|
|
{
|
|
warning ("stopped at unknown breakpoint while handling shared libraries");
|
|
}
|
|
|
|
return (status);
|
|
}
|
|
|
|
#endif /* #ifdef SVR4_SHARED_LIBS */
|
|
|
|
/*
|
|
|
|
LOCAL FUNCTION
|
|
|
|
enable_break -- arrange for dynamic linker to hit breakpoint
|
|
|
|
SYNOPSIS
|
|
|
|
int enable_break (void)
|
|
|
|
DESCRIPTION
|
|
|
|
Both the SunOS and the SVR4 dynamic linkers have, as part of their
|
|
debugger interface, support for arranging for the inferior to hit
|
|
a breakpoint after mapping in the shared libraries. This function
|
|
enables that breakpoint.
|
|
|
|
For SunOS, there is a special flag location (in_debugger) which we
|
|
set to 1. When the dynamic linker sees this flag set, it will set
|
|
a breakpoint at a location known only to itself, after saving the
|
|
original contents of that place and the breakpoint address itself,
|
|
in it's own internal structures. When we resume the inferior, it
|
|
will eventually take a SIGTRAP when it runs into the breakpoint.
|
|
We handle this (in a different place) by restoring the contents of
|
|
the breakpointed location (which is only known after it stops),
|
|
chasing around to locate the shared libraries that have been
|
|
loaded, then resuming.
|
|
|
|
For SVR4, the debugger interface structure contains a member (r_brk)
|
|
which is statically initialized at the time the shared library is
|
|
built, to the offset of a function (_r_debug_state) which is guaran-
|
|
teed to be called once before mapping in a library, and again when
|
|
the mapping is complete. At the time we are examining this member,
|
|
it contains only the unrelocated offset of the function, so we have
|
|
to do our own relocation. Later, when the dynamic linker actually
|
|
runs, it relocates r_brk to be the actual address of _r_debug_state().
|
|
|
|
The debugger interface structure also contains an enumeration which
|
|
is set to either RT_ADD or RT_DELETE prior to changing the mapping,
|
|
depending upon whether or not the library is being mapped or unmapped,
|
|
and then set to RT_CONSISTENT after the library is mapped/unmapped.
|
|
*/
|
|
|
|
static int
|
|
enable_break ()
|
|
{
|
|
int success = 0;
|
|
|
|
#ifndef SVR4_SHARED_LIBS
|
|
|
|
int j;
|
|
int in_debugger;
|
|
|
|
/* Get link_dynamic structure */
|
|
|
|
j = target_read_memory (debug_base, (char *) &dynamic_copy,
|
|
sizeof (dynamic_copy));
|
|
if (j)
|
|
{
|
|
/* unreadable */
|
|
return (0);
|
|
}
|
|
|
|
/* Calc address of debugger interface structure */
|
|
|
|
debug_addr = (CORE_ADDR) dynamic_copy.ldd;
|
|
|
|
/* Calc address of `in_debugger' member of debugger interface structure */
|
|
|
|
flag_addr = debug_addr + (CORE_ADDR) ((char *) &debug_copy.ldd_in_debugger -
|
|
(char *) &debug_copy);
|
|
|
|
/* Write a value of 1 to this member. */
|
|
|
|
in_debugger = 1;
|
|
write_memory (flag_addr, (char *) &in_debugger, sizeof (in_debugger));
|
|
success = 1;
|
|
|
|
#else /* SVR4_SHARED_LIBS */
|
|
|
|
#ifdef BKPT_AT_SYMBOL
|
|
|
|
struct minimal_symbol *msymbol;
|
|
char **bkpt_namep;
|
|
asection *interp_sect;
|
|
|
|
/* First, remove all the solib event breakpoints. Their addresses
|
|
may have changed since the last time we ran the program. */
|
|
remove_solib_event_breakpoints ();
|
|
|
|
#ifdef SVR4_SHARED_LIBS
|
|
interp_text_sect_low = interp_text_sect_high = 0;
|
|
interp_plt_sect_low = interp_plt_sect_high = 0;
|
|
|
|
/* Find the .interp section; if not found, warn the user and drop
|
|
into the old breakpoint at symbol code. */
|
|
interp_sect = bfd_get_section_by_name (exec_bfd, ".interp");
|
|
if (interp_sect)
|
|
{
|
|
unsigned int interp_sect_size;
|
|
char *buf;
|
|
CORE_ADDR load_addr;
|
|
bfd *tmp_bfd;
|
|
CORE_ADDR sym_addr = 0;
|
|
|
|
/* Read the contents of the .interp section into a local buffer;
|
|
the contents specify the dynamic linker this program uses. */
|
|
interp_sect_size = bfd_section_size (exec_bfd, interp_sect);
|
|
buf = alloca (interp_sect_size);
|
|
bfd_get_section_contents (exec_bfd, interp_sect,
|
|
buf, 0, interp_sect_size);
|
|
|
|
/* Now we need to figure out where the dynamic linker was
|
|
loaded so that we can load its symbols and place a breakpoint
|
|
in the dynamic linker itself.
|
|
|
|
This address is stored on the stack. However, I've been unable
|
|
to find any magic formula to find it for Solaris (appears to
|
|
be trivial on GNU/Linux). Therefore, we have to try an alternate
|
|
mechanism to find the dynamic linker's base address. */
|
|
tmp_bfd = bfd_openr (buf, gnutarget);
|
|
if (tmp_bfd == NULL)
|
|
goto bkpt_at_symbol;
|
|
|
|
/* Make sure the dynamic linker's really a useful object. */
|
|
if (!bfd_check_format (tmp_bfd, bfd_object))
|
|
{
|
|
warning ("Unable to grok dynamic linker %s as an object file", buf);
|
|
bfd_close (tmp_bfd);
|
|
goto bkpt_at_symbol;
|
|
}
|
|
|
|
/* We find the dynamic linker's base address by examining the
|
|
current pc (which point at the entry point for the dynamic
|
|
linker) and subtracting the offset of the entry point. */
|
|
load_addr = read_pc () - tmp_bfd->start_address;
|
|
|
|
/* Record the relocated start and end address of the dynamic linker
|
|
text and plt section for in_svr4_dynsym_resolve_code. */
|
|
interp_sect = bfd_get_section_by_name (tmp_bfd, ".text");
|
|
if (interp_sect)
|
|
{
|
|
interp_text_sect_low =
|
|
bfd_section_vma (tmp_bfd, interp_sect) + load_addr;
|
|
interp_text_sect_high =
|
|
interp_text_sect_low + bfd_section_size (tmp_bfd, interp_sect);
|
|
}
|
|
interp_sect = bfd_get_section_by_name (tmp_bfd, ".plt");
|
|
if (interp_sect)
|
|
{
|
|
interp_plt_sect_low =
|
|
bfd_section_vma (tmp_bfd, interp_sect) + load_addr;
|
|
interp_plt_sect_high =
|
|
interp_plt_sect_low + bfd_section_size (tmp_bfd, interp_sect);
|
|
}
|
|
|
|
/* Now try to set a breakpoint in the dynamic linker. */
|
|
for (bkpt_namep = solib_break_names; *bkpt_namep != NULL; bkpt_namep++)
|
|
{
|
|
sym_addr = bfd_lookup_symbol (tmp_bfd, *bkpt_namep);
|
|
if (sym_addr != 0)
|
|
break;
|
|
}
|
|
|
|
/* We're done with the temporary bfd. */
|
|
bfd_close (tmp_bfd);
|
|
|
|
if (sym_addr != 0)
|
|
{
|
|
create_solib_event_breakpoint (load_addr + sym_addr);
|
|
return 1;
|
|
}
|
|
|
|
/* For whatever reason we couldn't set a breakpoint in the dynamic
|
|
linker. Warn and drop into the old code. */
|
|
bkpt_at_symbol:
|
|
warning ("Unable to find dynamic linker breakpoint function.\nGDB will be unable to debug shared library initializers\nand track explicitly loaded dynamic code.");
|
|
}
|
|
#endif
|
|
|
|
/* Scan through the list of symbols, trying to look up the symbol and
|
|
set a breakpoint there. Terminate loop when we/if we succeed. */
|
|
|
|
breakpoint_addr = 0;
|
|
for (bkpt_namep = bkpt_names; *bkpt_namep != NULL; bkpt_namep++)
|
|
{
|
|
msymbol = lookup_minimal_symbol (*bkpt_namep, NULL, symfile_objfile);
|
|
if ((msymbol != NULL) && (SYMBOL_VALUE_ADDRESS (msymbol) != 0))
|
|
{
|
|
create_solib_event_breakpoint (SYMBOL_VALUE_ADDRESS (msymbol));
|
|
return 1;
|
|
}
|
|
}
|
|
|
|
/* Nothing good happened. */
|
|
success = 0;
|
|
|
|
#endif /* BKPT_AT_SYMBOL */
|
|
|
|
#endif /* !SVR4_SHARED_LIBS */
|
|
|
|
return (success);
|
|
}
|
|
|
|
/*
|
|
|
|
GLOBAL FUNCTION
|
|
|
|
solib_create_inferior_hook -- shared library startup support
|
|
|
|
SYNOPSIS
|
|
|
|
void solib_create_inferior_hook()
|
|
|
|
DESCRIPTION
|
|
|
|
When gdb starts up the inferior, it nurses it along (through the
|
|
shell) until it is ready to execute it's first instruction. At this
|
|
point, this function gets called via expansion of the macro
|
|
SOLIB_CREATE_INFERIOR_HOOK.
|
|
|
|
For SunOS executables, this first instruction is typically the
|
|
one at "_start", or a similar text label, regardless of whether
|
|
the executable is statically or dynamically linked. The runtime
|
|
startup code takes care of dynamically linking in any shared
|
|
libraries, once gdb allows the inferior to continue.
|
|
|
|
For SVR4 executables, this first instruction is either the first
|
|
instruction in the dynamic linker (for dynamically linked
|
|
executables) or the instruction at "start" for statically linked
|
|
executables. For dynamically linked executables, the system
|
|
first exec's /lib/libc.so.N, which contains the dynamic linker,
|
|
and starts it running. The dynamic linker maps in any needed
|
|
shared libraries, maps in the actual user executable, and then
|
|
jumps to "start" in the user executable.
|
|
|
|
For both SunOS shared libraries, and SVR4 shared libraries, we
|
|
can arrange to cooperate with the dynamic linker to discover the
|
|
names of shared libraries that are dynamically linked, and the
|
|
base addresses to which they are linked.
|
|
|
|
This function is responsible for discovering those names and
|
|
addresses, and saving sufficient information about them to allow
|
|
their symbols to be read at a later time.
|
|
|
|
FIXME
|
|
|
|
Between enable_break() and disable_break(), this code does not
|
|
properly handle hitting breakpoints which the user might have
|
|
set in the startup code or in the dynamic linker itself. Proper
|
|
handling will probably have to wait until the implementation is
|
|
changed to use the "breakpoint handler function" method.
|
|
|
|
Also, what if child has exit()ed? Must exit loop somehow.
|
|
*/
|
|
|
|
void
|
|
solib_create_inferior_hook()
|
|
{
|
|
/* If we are using the BKPT_AT_SYMBOL code, then we don't need the base
|
|
yet. In fact, in the case of a SunOS4 executable being run on
|
|
Solaris, we can't get it yet. find_solib will get it when it needs
|
|
it. */
|
|
#if !(defined (SVR4_SHARED_LIBS) && defined (BKPT_AT_SYMBOL))
|
|
if ((debug_base = locate_base ()) == 0)
|
|
{
|
|
/* Can't find the symbol or the executable is statically linked. */
|
|
return;
|
|
}
|
|
#endif
|
|
|
|
if (!enable_break ())
|
|
{
|
|
warning ("shared library handler failed to enable breakpoint");
|
|
return;
|
|
}
|
|
|
|
#if !defined(SVR4_SHARED_LIBS) || defined(_SCO_DS)
|
|
/* SCO and SunOS need the loop below, other systems should be using the
|
|
special shared library breakpoints and the shared library breakpoint
|
|
service routine.
|
|
|
|
Now run the target. It will eventually hit the breakpoint, at
|
|
which point all of the libraries will have been mapped in and we
|
|
can go groveling around in the dynamic linker structures to find
|
|
out what we need to know about them. */
|
|
|
|
clear_proceed_status ();
|
|
stop_soon_quietly = 1;
|
|
stop_signal = TARGET_SIGNAL_0;
|
|
do
|
|
{
|
|
target_resume (-1, 0, stop_signal);
|
|
wait_for_inferior ();
|
|
}
|
|
while (stop_signal != TARGET_SIGNAL_TRAP);
|
|
stop_soon_quietly = 0;
|
|
|
|
#if !defined(_SCO_DS)
|
|
/* We are now either at the "mapping complete" breakpoint (or somewhere
|
|
else, a condition we aren't prepared to deal with anyway), so adjust
|
|
the PC as necessary after a breakpoint, disable the breakpoint, and
|
|
add any shared libraries that were mapped in. */
|
|
|
|
if (DECR_PC_AFTER_BREAK)
|
|
{
|
|
stop_pc -= DECR_PC_AFTER_BREAK;
|
|
write_register (PC_REGNUM, stop_pc);
|
|
}
|
|
|
|
if (!disable_break ())
|
|
{
|
|
warning ("shared library handler failed to disable breakpoint");
|
|
}
|
|
|
|
if (auto_solib_add)
|
|
solib_add ((char *) 0, 0, (struct target_ops *) 0);
|
|
#endif /* ! _SCO_DS */
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
|
|
LOCAL FUNCTION
|
|
|
|
special_symbol_handling -- additional shared library symbol handling
|
|
|
|
SYNOPSIS
|
|
|
|
void special_symbol_handling (struct so_list *so)
|
|
|
|
DESCRIPTION
|
|
|
|
Once the symbols from a shared object have been loaded in the usual
|
|
way, we are called to do any system specific symbol handling that
|
|
is needed.
|
|
|
|
For SunOS4, this consists of grunging around in the dynamic
|
|
linkers structures to find symbol definitions for "common" symbols
|
|
and adding them to the minimal symbol table for the runtime common
|
|
objfile.
|
|
|
|
*/
|
|
|
|
static void
|
|
special_symbol_handling (so)
|
|
struct so_list *so;
|
|
{
|
|
#ifndef SVR4_SHARED_LIBS
|
|
int j;
|
|
|
|
if (debug_addr == 0)
|
|
{
|
|
/* Get link_dynamic structure */
|
|
|
|
j = target_read_memory (debug_base, (char *) &dynamic_copy,
|
|
sizeof (dynamic_copy));
|
|
if (j)
|
|
{
|
|
/* unreadable */
|
|
return;
|
|
}
|
|
|
|
/* Calc address of debugger interface structure */
|
|
/* FIXME, this needs work for cross-debugging of core files
|
|
(byteorder, size, alignment, etc). */
|
|
|
|
debug_addr = (CORE_ADDR) dynamic_copy.ldd;
|
|
}
|
|
|
|
/* Read the debugger structure from the inferior, just to make sure
|
|
we have a current copy. */
|
|
|
|
j = target_read_memory (debug_addr, (char *) &debug_copy,
|
|
sizeof (debug_copy));
|
|
if (j)
|
|
return; /* unreadable */
|
|
|
|
/* Get common symbol definitions for the loaded object. */
|
|
|
|
if (debug_copy.ldd_cp)
|
|
{
|
|
solib_add_common_symbols (debug_copy.ldd_cp);
|
|
}
|
|
|
|
#endif /* !SVR4_SHARED_LIBS */
|
|
}
|
|
|
|
|
|
/*
|
|
|
|
LOCAL FUNCTION
|
|
|
|
sharedlibrary_command -- handle command to explicitly add library
|
|
|
|
SYNOPSIS
|
|
|
|
static void sharedlibrary_command (char *args, int from_tty)
|
|
|
|
DESCRIPTION
|
|
|
|
*/
|
|
|
|
static void
|
|
sharedlibrary_command (args, from_tty)
|
|
char *args;
|
|
int from_tty;
|
|
{
|
|
dont_repeat ();
|
|
solib_add (args, from_tty, (struct target_ops *) 0);
|
|
}
|
|
|
|
#endif /* HAVE_LINK_H */
|
|
|
|
void
|
|
_initialize_solib()
|
|
{
|
|
#ifdef HAVE_LINK_H
|
|
|
|
add_com ("sharedlibrary", class_files, sharedlibrary_command,
|
|
"Load shared object library symbols for files matching REGEXP.");
|
|
add_info ("sharedlibrary", info_sharedlibrary_command,
|
|
"Status of loaded shared object libraries.");
|
|
|
|
add_show_from_set
|
|
(add_set_cmd ("auto-solib-add", class_support, var_zinteger,
|
|
(char *) &auto_solib_add,
|
|
"Set autoloading of shared library symbols.\n\
|
|
If nonzero, symbols from all shared object libraries will be loaded\n\
|
|
automatically when the inferior begins execution or when the dynamic linker\n\
|
|
informs gdb that a new library has been loaded. Otherwise, symbols\n\
|
|
must be loaded manually, using `sharedlibrary'.",
|
|
&setlist),
|
|
&showlist);
|
|
|
|
add_show_from_set
|
|
(add_set_cmd ("solib-absolute-prefix", class_support, var_filename,
|
|
(char *) &solib_absolute_prefix,
|
|
"Set prefix for loading absolute shared library symbol files.\n\
|
|
For other (relative) files, you can add values using `set solib-search-path'.",
|
|
&setlist),
|
|
&showlist);
|
|
add_show_from_set
|
|
(add_set_cmd ("solib-search-path", class_support, var_string,
|
|
(char *) &solib_search_path,
|
|
"Set the search path for loading non-absolute shared library symbol files.\n\
|
|
This takes precedence over the environment variables PATH and LD_LIBRARY_PATH.",
|
|
&setlist),
|
|
&showlist);
|
|
|
|
#endif /* HAVE_LINK_H */
|
|
}
|